1. Field of the Invention
The present invention relates to a design drawing transmission system for transmitting a design drawing through a communication line and exactly printing an exact reproduction on a receiving side of the communications line.
2. Description of the Related Art
Conventionally, in cases where a design drawing is to be used commonly among plural factories, or where a design division is located in Japan and a production factory is located abroad, if any modification is made to the design drawing, the revised version of the design drawing is mailed to receiving parties.
However, it takes a long time to mail the design drawing so that if the design modification is frequently made, mailing of the design drawing is very inconvenient. Further, a system is proposed in which design modification is carried out by transmitting the data prepared by a CAD (Computer Aided Design) system, which is a design system using a computer, through a communication line. However, this system also has problems such that the same CAD system must be also installed on the side of factory, resulting in the entire system being too large or if different CAD systems are introduced into respective factories, data cannot be shared by these factories so that the modification to the design drawing cannot be made rapidly. Thus, a more simplified design drawing transmission system has been greatly demanded.
Incidentally, a drawing can be transmitted through a facsimile machine. A prevailing facsimile machine, however, can only transmit a drawing up to A3 size so that it is not suitable to transmit the design drawing. Further, a transmitted drawing and a received drawing are not always in one-to-one correspondence. For this reason, the facsimile machine is not suitable to transmit the design drawing which is required to have exact dimensions.
Furthermore, in the case where a design drawing is transmitted between the different countries such as between Japan and U.S.A., a transmission side reads a design drawing by a drawing read means to prepare an image signal indicative of the drawing and transmits the image signal and a receiving side receives the image signal and reproduces the original design drawing by a drawing reproduction means. In this case, any disagreement in standard or characteristics between the drawing read means on the transmission side and the drawing reproduction means on the receiving side may give rise to unallowable errors in dimensions between the reproduced design drawing and the original design drawing due to the difference between the reading characteristics and the reproduction characteristics. Actually, this dimension error should be less than 0.5 mm (preferably 0.3 mm) per 1000 mm. But the above difference can provide a dimension error upto 20 mm per 1000 mm which is much lower than the desired accuracy.